Telephone-exchange plug.



A. MARR.I TELEPHONE EXCHANGE PLUG.

APPLICATION FILED AUG. I2. 1915.

1,237,358. Patentedmlg 21,1917.

AIIIEXAITDEIR.-1\llI.ARIR., OF MANCHESTER, ENGLAND.

TELEPHONE-EXCHANGE PLUG.

Application :nea August 12, 1915. serial No. 455,165.

To all whom t may concern.'

Be it known that I, ALEXANDER MARR, a subject of the King of Great Britain and Ireland, and a resident of Manchester, in the county of Lancaster, England, haveinvented a new and useful Telephone-Exphanve Plug, of which the following is a speci cation.

This invention relatesto telephone plugs. In the telephone exchange plug most commonly used the flexible cord containing the conductors leaves the extreme 'rear end of the plug and vthe conductors are frequently broken at the point where the cord leaves the plug owing to the sharp bending (practically at right angles) of the cord to the plug when the latter is inserted in the switchboard, and the operator pressing the palm of the hand against the rear end of the plug when inserting the latter and thereby nipping or crushing the cord and contained conductors between the hand and the end of the plug. The principal object of the present invention is to provide a plug capable of being inserted by pressing the palm of the hand against its rear end without nipping or\crushing the flexible cord, and which can, when withdrawn and not in use, turn into line with the cord. A further object of the invention is to protect the metal plug itself against damage on hasty insertion into' or withdrawal from the switchboard.

According to` this inventionV the tubular body of the plug is extended rearwardly to forman elongated handle which is open at its rear end and has provided in its wall a longitudinal slot ywhich communicates with the open end and out through which the cord passes laterally in advance of said end n when the plug is held horizontally.

I will more fully describe my invention lwith reference to the accompanying drawing wherein-'- Figure 1 is a plan xof one form of improved tele hone exchange plug,

lig. 2Y a ongitudinal sectional elevation, an

Fig. 3 an end elevation of the same.

Fig. 4 is'a part lon 'tudinal section of a plug having a strength-lening ferrule placed around it in its wea est part.

Referring to Figs. 1 to 3, A is the telehone exchange plug and B the tubular body of non-magnetic metal, ebonite, ber

or other suitable material into which the- Specication of Letters Patent.

Patented Aug. 21, 191'?.

rear portion of the plug is inserted and which is extended rearwardly at B to serve 'as an elongated handle for the plug. The `extension B has an internal diameter'lar er than the external diameter of the lexi le cord 'C which carries the line wire secured to the terminal on the plug and the battery wire making contact with the plug itself.

The end of the extension B is open and in the wall of the extension there is provided l'a slot D of suitable length communicating with the open end and out through which the cord C can pass laterally at some distance from said end against which the palm of the hand of the switchboard operator would be pressed in inserting the plug.

When' the operator holds the plug in a horizontal position ready for insertion into the switchboard the flexible cord passes out through the slot D and hangs ldown approximately at right angles to the plu as shown in Fig. 2, and well out of reac of the hand and the plug can be inserted by pressing the hand a ainst the rear end of the tube B withoutnlpping or crushing the cord C.

The metal plug A is made to fit snugly into the cover B and may be secured in position in any suitable manner. In Figs. 1 and 2 set-screws H are used.

As shown in Figs. 1 and 2 the tubular b ody is so Varranged in relation to the plug that the width of the slot D is at right angles to the surface formed by cutting away the rear end of the lug to accommodate the terminals M, lill. In consequence of the definite arrangement of the cord with regard to the plug the operator will always insert the plug in approximately the same position into the switchboard, the largest diameter of the plug will always be approximately vertical, and breakages in consequence of the plu having been inserted with the flat part 1n a horizontal position and having een carelessly withdrawn will be effectively avoided.

In order to strengthen the tubular body B at its front end which is its weakest part I mount thereon a metallic ferrule H1 Fig. 4. The periphery of the ferrule may project beyondv the periphery of thetubular body B as shown, or may be flush therewith, and the' ferrule may be screwed, forced or be otherwise suitably secured in position on the tubular body and the latter may be provided with one or more slits to` give it some only thefront end of the tubular bod lar body B I may employ a` device compris-V it may be extended as a sheath to the W ole or any part of the body.V For gripping `the cord C within the tubuingvan abutment F integralwith orfsecured in the body, by screws F1 or otherwise, and provided with conical bore, and a compleinentary conical sleeve Gr of india rubber on the cord C. .Such gripping device is already well known and I 'make no claim thereto. I may employ lany other suitable gripping means.

1. The improved telephone exchange plug comprisixg afetal plug, atubular body in which said plug is'mounted, flexible conductors passing into said tubular body and connected to the plug therein, and a rearward, extension to said tubular bodyk open at its rear end and provided with a longitudinal slot in its wall which extends to saidlrear end and'through which said conductors pass laterally in advance of said rear end when the plug is held horizontal, said conductors passing axiallyinto said ex 8o `tension when'the yplug is held vertical.

2. The improved telephone exchange v lug comprising a metal plug, `,a tubular bo y in which said plug is fitted and provided with a rearward extension open at its reari end and provided in its -wall with a slot extending to said rear end, and flexible conductors passing into said extension and body to the `metal plug in the latter, said conductors passing through said slot in advance of the rear end of said extension when the plug is held horizontal and passing axially into s'a'iId extension when the plug is held verti- C.

3. The improved telephone plug comprising a metal plug, a tubular' body in which said plug is fitted and extended rearwardly to form a handle whereby the plug vmay be manipulated and provided with a longitudinal slot in its 'wall extending to its rear end, and flexible conductors passin into said extension and body to the metal plug in the latter, said conductors passing laterally through said slot in advance of the rear end of said extension when the plug Ais held horizontal and passing axially into saild extension when the plug is held v vertica 4. The improved telephone exchange lug comprisin a metal plug, a tubular bo y in which sai lug is mounted,iexible conductors passlng into said tubular vbody and connected to the plug therein, a rearward extension to said tubular body open at its rear end and provided with a longitudinal vslot in its wall which extends to said rear end. and through which said conductors pass laterally in advance of said rear end when the plug is held horizontal, said conductors passing axially into 'said extension when' the plugl is held vertical, and a strengthening metalferrule on said'tubular body.

In witness whereofI have hereunto set my hand. i 

